Piner Mikuni

[tlanders]

Dwight says not to go bigger than 32mm on the Piner. What happens if you do? What is the correct jetting for a Piner with a 32mm Mikuni? No one really answered this question in SkipperClydes thread below. Also, no one ever answered Mark Annans thread on August 5 about jet sizing on a 28mm Mikuni for a B engine Sachs Six Day. Does anyone know? Thanks for your help.

Teddy

 

[john durrill]

To go bigger than 32 mm on the carb , would give you a loss except a high rpm on performance. If you have ever done some Hot Rodding I think you will understand. For any V8 set up for less than 300 HP you only need a 600 cfm carb. bigger will only use more fuel and cause drivability problems. It has to do with air flow through the carb venturi and engine vaccuum.
  It would be hard to give you a baseline on Jetting for your carb unless someone has the same model ( bike and Carb). Round slides jet different than flat slides.
 If you can get a type 54 bing in 32 mm or an amal someone hear should have the jetting info you would need.
 I can ask the men in the vinenduro group and see if some one their has a 175 thats been changed to a mikuni if you like.One of the members might have just the info you would need.
 Same with the 125 and a 28 mm conversion for it. does it have an MX pipe or the standard enduro version?

 

[john durrill]

tlander,
put a message on the group board about your carb's. will give you any information they come up with.
best of luck,
John

 

[tlanders]

John,

Thanks for the speedy response. I hope someone does have the jetting for the 32mm Mikuni on a Piner. The Piner has the enduro pipe, the six day has an aluminum motocross pipe. Teddy

 

[john durrill]

The MX pipe will change the jetting even on a stock carb. but most times its with in a jet size or two. the key to the Mikuni is gettin the right needle and needle jet. it's not much trouble to do the main and pilot, but the needle or neddle jet could be so far off you could spend a tiddy sum on parts and
a lot of time getting it right. the slide could have to be changed also. much better to get the base line from some one who has already done it.
john

 

[skipperclyde]

I once called Rick M. in Peoria about the 125 jetting.  He said he used the standard jetting that came with the carb and only changed the main jet as needed.  

He does own a 250 but I don't know what carb he has on it.  You may want to give him a call.

The lost 1-7 last night.  Jason played half the game in goal, did great, only gave up two goals.  The first was on a PK after his brother tripped someone in the box, what are brothers for. The second on a break away.  Had some great stops.

 

[tlanders]

Phil,

Was Jason the keeper of the Varsity game? Good work Jason!!!!

The 32mm Mikuni I have has a #30 pilot jet, a 6FJ6 needle, a P8-159 needle jet, and an unmarked main jet. I called Sudco and they said that the main must be aftermarket because all their main jets are marked. With a numbered drill set I measured the main and it was the same size as a #42 drill or 0.093" diameter. I would still like to hear of any other Piner with a 32mm Mikuni and what the jetting is before I put this carb in service.

Thanks all, Teddy

 

[john durrill]

Teddy,
i am looking at my Sudco catalog,
the needle jet you have is in the middle of the chart. the needle is two steps richer from center in the chart. Does the 32 you have fit ? ( no clearance problems when mounted? if it does. , i would call Sudco,
givethem the model carb you have ( example VM 30-83 or VM32-33. Ask them what base line jetting they recommend. Every thing including the slide cutaway.( it on the bottom of the slide * IE 2.5 etc*. get one of their catalogs headed your way. It has a wealth of info on tuneing and all they offer in the way of sizes in jets and needles. you will need all this even if someone can give you a setup that works and it will help you fine tune the carb once you get it on and running.
Something to bear in mind if the carb dosent fit quit right. a 32 mm Mikuni may flow a lot more air than a 32 Bing. if thats the case smaller would be better. Sudco can give you the dimensions of the 30 and 32 carbs.
hope this helps till we can find some one with a piner and a mikuni setup.
John